列举常用数据结构：数组、链表、栈、堆、二叉树、红黑树

给定一个链表，返回链表开始入环的第一个节点。 如果链表无环，则返回 null。
为了表示给定链表中的环，我们使用整数 pos 来表示链表尾连接到链表中的位置（索引从 0 开始）。 如果 pos 是 -1，则在该链表中没有环。
说明：不允许修改给定的链表。

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二分查找利用已排好序的数组，每一次查找都可以将查找范围减半。查找范围内只剩一个数据时查找结束。

给定一个链表，旋转链表，将链表每个节点向右移动 k 个位置，其中 k 是非负数。

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给定一个整数数组 nums 和一个目标值 target，请你在该数组中找出和为目标值的那两个整数，并返回他们的数组下标。
你可以假设每种输入只会对应一个答案。但是，你不能重复利用这个数组中同样的元素。

示例:给定 nums = [2, 7, 11, 15], target = 9
因为 nums[0] + nums[1] = 2 + 7 = 9，所以返回 [0, 1]

卷积神经网络(Convolutional Neural Networks, ConvNets or CNNs)是一种在图像识别与分类领域被证明特别有效的神经网络。卷积网络已经成功地识别人脸、物体、交通标志，应用在机器人和无人车等载具。

从RQAlpha开源量化投资框架的代码结构、技术选型、回测流程、撮合机制等多个方面分析。

量化投资学习笔记-量化策略

整理量化投资学习笔记-期货

整理TensorFlow学习笔记

整理机器学习数据清洗与特征处理相关知识

Go is not meant to innovate programming theory. It’s
meant to innovate programming practice. — Samuel Tesla

整理Hadoop和Spark的设计理念，组成模块，集群架构，应用场景；
Spark生态齐全，从数据系统Lambda架构的角度，更具优势

An AVL tree is a self-balancing binary search tree, and it was the first such data structure to be invented.

The AVL tree is named after its two Soviet inventors, Georgy Adelson-Velsky and Evgenii Landis, who published it in their 1962 paper “An algorithm for the organization of information“.

An AVL tree is a self-balancing binary search tree, and it was the first such data structure to be invented.
In an AVL tree, the heights of the two child subtrees of any node differ by at most one.
AVL trees are often compared with red-black trees because they support the same set of operations and because red-black trees also take O(log n) time for the basic operations. Because AVL trees are more rigidly balanced, they are faster than red-black trees for lookup intensive applications.
However, red-black trees are faster for insertion and removal.

Kafka is used for building real-time data pipelines and streaming apps. It is horizontally scalable, fault-tolerant, wicked fast, and runs in production in thousands of companies.

B-tree is a tree data structure that keeps data sorted and allows searches,sequential access, insertions, and deletions in logarithmic time. The B-tree is a generalization of a binary search tree in that a node can have more than two children. Unlike self-balancing binary search trees, the B-tree is optimized for systems that read and write large blocks of data. It is commonly used in databases and file-systems

B-树是一类树，包括B-树、B+树、B*树等，是一棵自平衡的搜索树，它类似普通的平衡二叉树，不同的一点是B-树允许每个节点有更多的子节点。B-树是专门为外部存储器设计的，如磁盘，它对于读取和写入大块数据有良好的性能，所以一般被用在文件系统及数据库中。

Kafka is used for building real-time data pipelines and streaming apps. It is horizontally scalable, fault-tolerant, wicked fast, and runs in production in thousands of companies.

记录数据预处理，特征向量化的一些常见方法

列举关系型数据库MySQL的InnoDB和MyISAM索引的实现和